Vitreoretinal surgery is an invasive microsurgical ocular procedure utilized to correct problems at or near the back of the eye. It is particularly useful for correcting retinal disorders, such as removal of various types of potentially vision-impairing or destructive epiretinal membranes (ERMs). In this type of ophthalmic surgery (pars plana vitrectomy), surgeons access the back of the eye through standard procedures and utilize various instruments, for example, a “retinal rake”, to remove these membrane(s) by scraping or scouring the surface of the retina.
When conducting vitreoretinal surgeries it is important to remove, manipulate and/or contact only diseased or scarred tissue to minimize damage to healthy surrounding or underlying tissues. As expected, this is especially important when addressing problems of, or near, the retina.
Prior to such surgeries, a pre-surgical image is often obtained, such as a fluoroscein image, of the pertinent ocular structure, such as the eye retina. This can provide a surgeon with information about the type and/or extent (e.g., depth, area, etc.) of the membrane or other tissue to be removed. During surgery, a slit lamp is usually utilized to view the interior of the eye while a surgeon manually removes the epiretinal membranes. The surgeon must often rely on experience and visual observation, through the slit lamp or other visual device, to determine where and how much material to remove. There is little, if any, other feedback to a surgeon during the procedure as to what type of tissues are being touched or manipulated.
This difficulty in differentiating between tissue types creates challenges in other types of surgeries including, for example, surgeries to remove tissue adjacent to nervous system tissue.
Therefore, a need exists for a surgical instrument capable of providing a secondary signal to surgeons to distinguish between touching healthy eye tissue and tissue that needs to be removed. In particular, there exists a need for a retinal rake or similar device that can identify epiretinal membranes (ERMs) and retinal tissue and provide a signal to indicate which tissue is in contact with the retinal rake.